Nokia has been working on the device since it announced in February that it would abandon its Symbian smartphone platform in favour of Microsoft's new Windows Phone mobile operating system. Now Elop is preparing to unveil the device on the first day of the Nokia World show being held at London's ExCel centre.

Industry sources have told the Guardian that it will use a micro-SIM – the narrow version of the card used by all mobile phones, but which has only been widely deployed in Apple's iPhone. That, sources say, will give Nokia some leverage in trying to tempt iPhone users whose contracts are ending or who want to shift across to the new platform a simpler way to transfer.

Shipments of the N9 began as Microsoft introduced its biggest update for Windows Phone 7 yet, with "Mango" software being rolled out to 98% of customers.

Nokia's N9 features an 8 megapixel camera, near-field communication (NFC) technology for mobile payments and up to 64GB of storage, as well as Nokia's standard turn-by-turn navigation software.

"Since we announced the N9 in June this year, the feedback [we've had] from discerning and avid smartphone users across the world has been nothing short of fantastic," said Ilari Nurmi, vice president of marketing at Nokia.

"With the innovations in industrial design, user interface and the Qt developer experience, the N9 sets the bar for how natural technology can feel, and represents the first in a number of products from Nokia that will be brought to life in similar fashion."

Asked whether the company had plans to launch the N9 in the UK, a Nokia spokesman said: "We have elected to ship the N9 to those markets we believe offer the most suitable conditions required for a successful launch."

The spokesman added that, after the N9, Nokia's "primary smartphone platform" will be Windows Phone, indicating that Meego software would be discontinued. He said: "[Windows] is where we will be focusing our energies and resources as we go forward. A lot of the innovation you can see in the N9 will continue to live on at Nokia in a variety of ways."

Developers reacted positively to the Mango update but suggested Nokia's new devices would find it difficult to live up to expectations.

"The number of new features and capabilities compared to the devices that came out barely a year ago is stunning," said Al Hilwa, programme director for apps development software at analysts IDC.

"Windows Phone developers and those from other ecosystems like Symbian will feel like kids in a candy store with this release. Being able to showcase data and numbers in a home screen tile with the prominence that the Metro interface has to be exciting."

He aded: "We are now bracing to see how exciting the devices will be, especially those from Nokia. The T-Mobile HTC device announced today is beautiful and a great start."